GB2177730A - Wire grille - Google Patents

Abstract

In a decorative wire grille, which consists of wires (1a-1e) which are bent in undulating lines about imaginary straight axes (2) parallel to one another and whose apex regions overlap and are welded together (at 3), for the zonewise control of rigidity a plurality of sinuous wires (1a and 1b) of the same wavelength are disposed coaxially and offset with respect to each other by the same fraction of a wavelength in at least one longitudinal zone. Optionally, in at least one other longitudinal zone only one corrugated wire (1d or 1e) is disposed. At the resulting wire crossing points (4) in the first mentioned longitudinal zones the wires are also welded. Three wires may be disposed on the same axis. A tensioning wire may be provided on a longitudinal edge of the grille, such wire being indented or having a sinuous shape of smaller amplitude than the wires (1) of the grille. <IMAGE>

Description

SPECIFICATION Wire grille The invention relates to a wire grille, which is particularly suitable as a decorative grille for fencing, and which consists of wires bent in undulating lines about imaginary straight axes, the straight axes of the undulating lines being spaced apart and extending parallel to one another, and the apex regions of adjacent sinuous wires overlapping and being welded together. Such a wire grille will hereinafter be referred to as "of the kind described".

Wire grilles of this kind, in which the wires extend in zigzag or sinusoidal lines, are known from US-A-2000788 (see in particular Figures 16, 24 and 35 1.c.) The sinuous wires in these known grilles may overlap in their apex regions to so slight an extent that in each of these regions they form only one weld point, but they may also overlap to such an extent that two separate weld points are formed (see Figures 26 and 35 1.c.).

In the practical use of such grilles, particularly for fencing purposes, insufficient rigidity of the grille has been found to be a disadvantage, especially when the sinuous wires follow a curved course. The sinuous wires can in fact easily be stretched, particularly in the axial direction, so that they readily bulge out through the action of a force directed at right angles to the surface of the grille. In order to obviate this shortcoming, it is possible, as is also known from US-A-2000788, for straight wires preventing the elongation of the corrugated wires (see Figures 23 and 25 1.c.) to be welded into the grille in the axial direction of the corrugated wires and optionally also at right angles to that direction.However, this method of stiffening the grille impairs the uniform appearance of decorative grilles, particularly when they are made of sinuous wires extending entirely over curved courses.

The invention provides another possible way of increasing the stiffness of wire grilles of the kind described above without correspondingly increasing the consumption of material, wherein only sinuous grille wires are used and at the same time the mesh of the grille can be reduced in size, as is frequently desirable.

In a grille of the kind described, according to the invention, a plurality of sinuous wires of the same wavelength are disposed substantially coaxially and offset with respect to each other by the same fraction of the wavelength, the wire crossing points thus formed between the apex regions of the sinuous wires also being welded.

Preferably, the wires are offset by a half or a third of the wavelength.

It has been found that the additional weld points obtained in this manner at the wire crossing points, where the wires extend at least approximately rectilinearly, achieve an approximation to the greater rigidly of welded diagonal grilles having a rhombic mesh.

It has been found that in practice wire grilles are also in demand which, instead of being substantially uniformly stiffened, are stiffened only in determined zones of the grille, particularly in the two edge zones and optionally in a middle zone. For example, stiffening of the edge zones of the grille is desirable when it is to be stretched out between posts as a fence. In addition, in this case stiffening in a middle zone of the grille may also be desired in order to make the fence less susceptible to bulging. In other cases, such as for example for framed wire grilies, stiffening zones may also be desired in other relative positions.

According to the invention this need can be met by providing in one or more first longitudinal zones of the grille, a plurality of sinuous wires of the same wavelength, which are disposed substantially coaxially and offset with respect to each other by the same fraction of a wavelength, whereas in one or more second longitudinal zones only one respective sinuous wire is disposed, the wire crossing points formed in the or each first longitudinal zone between the apex regions of the sinuous wires also being welded. Again the coaxial wires may be offset preferably by a half or a third of a wavelength in one or both edge zones and/or a middle zone.

With all the wire grilles according to the invention, not only are stiffened zones provided, but in addition an aesthetic effect can be achieved. Since the freestanding apex regions on the longitudinal edges of the grille are sensitive to bending of the plane of the grille, it is advisable for these apex regions to be welded to a longitudinal wire or to a pair of longitudinal wires, preferably to one which is elastically extensible in the longitudinal direction.

Examples of various embodiments of the invention will now be explained more fully with reference to the accompanying drawings, in which: Figure 1 is a face view of a known type of decorative grille; Figures 2 and 3 are face views of decorative grilles according to the invention; Figure 4 is a cross-section through a grille of this kind; Figures 5 and 6 show decorative grilles having stiffened edge zones, it being indicated in each case that the middle zone of the grille has been shortened in order to save space in the drawing; and, Figure 7 and 8 show decorative grilles in which the two edge zones and a middle zone are stiffened.

The known decorative grille shown in Figure 1 consists of wires 1 bent in sinusoidal lines, the imaginary axes 2 of the undulating lines being equally spaced apart by the distance A.

Adjacent sinuous wires are offset with respect to each other by half a wavelength, and the wave amplitudes are made so great that adjacent sinuous wires overlap in their apex regions and form in each case two wire crossing points 3 at which the wires are welded together. It can readily be seen that the grille illustrated can easily be stretched in the direction of the imaginary axes 2 of the undulating lines through the action of a tensile force P, because the relatively long curved portions of the sinuous wires between the apex regions can offer only slight resistance to the deformation necessary for that purpose.

In the decorative grille which is shown in Figure 2, two wires 1a, 1b, offset with respect to each other by half a wavelength are disposed along each of the imaginery axes 2, so that in comparison with Figure 1 there are twice the number of weld points 3 in the apex regions, whilst in addition further wire crossing points 4, which are likewise welded, are formed on the imaginary axes 2. If in an embodiment of the kind shown in Figure 2 the cross-section of the wire is made half as large as in the form of the construction shown in Figure 1, increased stiffness and in addition a smaller mesh is achieved, with the same consumption of material, because of the greater number of weld points 3 and the additional weld points 4 at the crossing points of practically straight portions of the wire.

Figure 3 shows a decorative grille in which in each case three sinuous wires 1a, 1b, 1c are disposed substantially coaxially and offset with respect to each other by a third of a wavelength, in such a manner that their apex regions overlap in each case at a weld point 3. The individual waves are again composed of straight portions and curved apex regions.

A large number of weld points 3 are formed in the apex regions of the sinuous wires, and in addition further weld points 5 are formed some distance from the imaginary wave axes 2 and from the apex regions.

Figure 4 shows a section on the line IV-IV in Figure 2. It can be seen that the neighbouring sinuous wires la, ib overlap in succession, in imbricated form, in their apex region in which the weld points 3 are situated, whereby the production of the grilles is simplified.

It is obvious that within the scope of the invention numerous variations are possible in respect of the number of coaxial sinuous wires, in respect of the path followed by the sinuous wires between their apex points, and in respect of the size of the overlap regions of the apices of the sinuous wires.

In the decorative grille shown in Figure 5, two wires la and 1b, sinusoidally bent with the same wavelength, are disposed along imaginary straight axes 2 and are offset with respect to each other by half a wavelength. In the middle zone of the grille single sinuous wires 1 d and 1 e respectively extend alternately parallel to the wires 1a and 1b respectively; the wires 1d and 1e are accordingly likewise offset by half a wavelength with respect to one another. The distances A between the imaginary straight axes are so selected that the apex regions of each two neighbouring corrugated wire la, 1b, ld and 1e intercross at two points 3". In addition, crossing points 4 are formed in the edge zones between approximately straight portions of the wires 1a and 1b.All wire crossing points 3 and 4 are welded together.

Figure 6 shows a similar decorative grille to that shown in Figure 5, with the exceptions that, instead of a sinusoidal waveform, a waveform consisting of straight lines and circular arcs is used, and that the distance A between the imaginary straight axes is made so great that the apex regions of neighbouring wires, for example of the wires 1b and 1d, are in contact with one another only at one point 3 in each case. In addition, in this example substantially straight longitudinal edge wires 6 are provided on both longitudinal edges of the grille in order to prevent bending of the apex regions of the wavy wires 1a, 1b, these wires 6 being welded at 8 to the apices of the wires 1a, 1b in the longitudinal edge zones and having depressions 7 ensuring elastic ex tensibiiity of the wires.

In the example shown in Figure 7 ail the wires la, 1b, and id forming the grille once again follow a path composed of straight lines and circular arcs, and in the two edge zones as well as in the middle zone two sinuous wires la, 1b are in each case disposed and are offset with respect to each other by half a wavelength, while in the intermediate zones only one wire id is provided in each case.At the top edge of the grille a longitudinal wire 8 is provided which, compared with the wires 1a, 1b and id, have a waveform with half the wavelength and with an amplitude a which is substantially smaller than the spacing A of the imaginary straight axes 2 or the amplitude of the waveform of wires 1a, ib and id. All the resulting points of contact 3, 4 and 10 of the wires 1a, 1b, id and 9 are welded.

Figure 8 shows a decorative grille in which three wires 1a, 1b and ic are disposed which are bent with the same wavelength and are uniformly offset along the imaginary axes 2 in the edge zones and in a middle zone, whereas in the intermediate zones there are once again alternately disposed in each case single wavy lines id and le respectively extending along the straight axes 2, these wires once again being offset relative to one another by half a wavelength. The distance A between the imaginary straight axes 2 is once again so selected in this example that in all the over lapped apex regions of the wires only one point of contact 3 is formed.The contact points 3 and also the additional crossing points 5 formed in the middle zone between the wires la, ib and ic are again welded together.

The wires of the grille may extend in any undulating lines, for example on a sinusoidal path. It is also possible for the diameter of the wire to be different in the edge zones and/or in the middle zone, and in particular to be larger, than in the other zones.

The preformed longitudinal edge wires 6 and 9 in Figures 6 and 7, which permit the tensioning of the grilles, may optionally also be replaced by straight longitudinal edges wires or by a pair of straight longitudinal edge wires. In some circumstances it may be expedient also to provide a straight longitudinal wire in grilles for the purpose of tensioning the grille and reducing the risk of bulging.

Finally, it would also be possible to dispose along at least one longitudinal zone or imaginary straight axis of the grille a determined plurality of sinuous wires uniformly offset relative to one another, to dispose along at least one other longitudinal zone or imaginary straight axis another plurality of sinuous wires uniformly offset relative to one another, and optionally to dispose along another longitudinal zone or imaginary straight axis a single sinuous wire, the whole arrangement merely having to be so disposed that the apex regions of sinuous wires lying next to one another in the direction of the width of the grille will in accordance with requirements overlap over the entire width of the grille. In this way the rigidity of the grille and its appearance can be still more widely varied.

Claims (11)

1. A wire grille, of the kind described, in which a plurality of sinuous wires of the same wavelength are disposed substantially coaxially and offset with respect to each other by the same fraction of the wavelength, and the wire crossing points thus formed between the apex regions of the sinuous wires also being welded.

2. A wire grille according to claim 1, in which the sinuous wires extend substantially sinusoidally.

3. A wire grille according to claim 1 or claim 2, in which the sinuous wires overlap in their apex regions to such an extent that they form two separate wire crossing points at both of which the wires are welded together.

4. A wire grille according to any of claims 1 to 3, in which the sinuous wires disposed along adjacent imaginary axes overlap in suc cession in imbricated form in their apex re gions.

5. A wire grille according to any of claims 1 to 4, in which in one or more first longitudinal zones of the grille, a plurality of sinuous wires of the same wavelength, are disposed sub stantially coaxially and offset with respect to each other by the same fraction of a wavelength, whereas in one or more second longitudinal zones only one respective sinuous wire is disposed, the wire crossing points formed in the or each first longitudinal zone between the apex regions of the sinuous wires also being welded.

6. A wire grille according to claim 5, in which the first longitudinal zones comprise both edge zones.

7. A wire grille according to claim 5 or claim 6, in which the first zones comprise a middle zone of the grille.

8. A wire grille according to any of claims 1 to 7, wherein the offset of the substantially coaxial wires is a half or a third of the wavelength.

9. A wire grille according to any of claims 1 to 8, in which, on at least one longitudinal edge of the grille, the apex regions of the corrugated wires are welded to a tensioning wire.

10. A wire grille according to claim 9, in which the tensioning wire is a substantially straight indented wire or a sinuous wire with a substantially smaller amplitude.

11. A wire grille substantially as described with reference to any of the examples shown in Figure 2 to 8 of the accompanying drawings.